The Cancer Blog

July 1, 2008, 9:43 PM CT

Cancer cells revert to normal at specific signal threshold

Cancer starts when key cellular signals run amok, driving uncontrolled cell growth. But researchers at the Stanford University School of Medicine report that lowering levels of one cancer signal under a specific threshold reverses this process in mice, returning tumor cells to their normal, healthy state. The finding could help target cancer chemotherapy to tumors while minimizing side effects for the body's healthy cells.

The scientists identified a precise threshold level of the signaling molecule Myc that determined the fate of tumor cells in a cancer of the immune system in mice. Above the threshold, high levels of Myc drove immune cells to grow too large and multiply uncontrollably. When the scientists lowered Myc levels below the threshold, the same cells shrank to normal size, stopped multiplying and began dying normally.

"This is a new concept," said Catherine Shachaf, PhD, an instructor in microbiology and immunology who shared lead authorship of the study with colleague Andrew Gentles, PhD, a research associate in radiology. Prior research demonstrated that turning Myc and other cancer signals all the way off can kill a tumor, but this is the first time researchers have demonstrated a specific midway point at which a cancer signal reverted to a healthy level, Shachaf said. The findings would be reported in the July 1 issue of Cancer Research........ Posted by: Andria      Read more         Source

July 1, 2008, 8:38 PM CT

Designer diet for prostate cancer

Eating one or more portions of broccoli every week can reduce the risk of prostate cancer, and the risk of localised cancer becoming more aggressive.

For the first time, a research group at the Institute of Food Research led by Professor Richard Mithen has provided an explanation of how eating broccoli might reduce cancer risk based upon studies in men, as opposed to trying to extrapolate from animal models. Prostate cancer is the most common non-skin cancer for males in western countries. The research has provided an insight into why eating broccoli can help men stay healthy.

For the study, published in the online, open-access journal PLoS ONE on July 2, men who were at risk of developing prostate cancer ate either 400g of broccoli or 400g of peas per week in addition to their normal diet over 12 months. Tissue samples were taken from their prostate gland before the start of the trial and after 6 and 12 months, and the expression of every gene measured using Affymetrix microarray technology.

It was found that there were more changes in gene expression in men who were on the broccoli-rich diet than on the pea diet, and these changes may be associated with the reduction in the risk of developing cancer, that has been reported in epidemiological studies......... Posted by: Andria      Read more         Source

June 17, 2008, 9:48 PM CT

Pinpointing Prostate Cancer Recurrence

A simple blood test may help doctors better predict whether prostate cancer will recur or spread in patients who have undergone surgery for the disease, UT Southwestern Medical Center scientists have found.

As per a research findings reported in the June 15 issue of Clinical Cancer Research, UT Southwestern researchers identified a panel of seven biomarkers that can predict with 86 percent accuracy which patients with prostate cancer will experience a recurrence and progression of the disease. Biomarkers are proteins circulating in a patient's blood that are specific to a disease.

Current risk assessment methods, which include stage and grade of cancer and the level of prostate-specific antigen, can predict prostate cancer recurrence with about 70 percent accuracy.

"There are several unresolved issues in the clinical and surgical management of prostate cancer, one of them being the identification of men who have insignificant cancers and can be followed, and another being the identification of men most likely to have spread of disease and early or late recurrence," said Dr. Claus Roehrborn, chairman of urology at UT Southwestern and one of the study's authors. "In the future, once we can reliably identify those patients, we may be able to offer additional therapy to counteract that risk and give those men a better chance for a permanent cure. The panel of biomarkers is an important step in this direction"......... Posted by: Andria      Read more         Source

June 10, 2008, 10:19 PM CT

'Addicted' cells provide early cancer diagnosis

Researchers at the Institute of Food Research have detected subtle changes that may make the bowel more vulnerable to the development of tumours.

With support from the Food Standards Agency and the Biotechnology and Biological Sciences Research Council they are investigating whether diet could control these changes and delay or reverse the onset of cancer.

"We looked at changes in 18 genes that play a role in the very earliest stages of colorectal cancer," says Professor Ian Johnson at the Institute of Food Research.

"We detected clear chemical differences in these genes in otherwise normal tissue in cancer patients.

"This represents a new way to identify defects that could eventually lead to cancer".

All cells carry a complete set of instructions for the whole organism in their nuclear DNA, but to define the specialised structure and functions of each particular cell type, genes must be switched on or firmly off, over the course of the cell's life-cycle.

One of the mechanisms controlling the activities of the genes in a cell is the "epigenetic code", a set of chemical tags attached to the DNA molecule, marking individual genes for expression, or for silence. It is well known that the abnormal behaviour of cancer cells is partly due to mistakes in this epigenetic code, some of which switch on genes for growth, whilst others switch off genes that would otherwise cause abnormal cells to destroy themselves......... Posted by: Andria      Read more         Source

May 22, 2008, 10:28 PM CT

Stabilizing cancer-fighting p53

HOUSTON - Efforts to protect the tumor-suppressor p53 could just as easily shelter a mutant version of the protein, causing cancer cells to thrive and spread rather than die, as per research by researchers at The University of Texas M. D. Anderson Cancer Center published in the current issue of the journal Genes and Development.

"As we develop therapies to restore the function of p53, we need to make sure we first know what version of this gene is present in a patient's tumor and then decide how to treat it," said senior author Guillermina Lozano, Ph.D., professor and chair of M. D. Anderson's Department of Cancer Genetics.

The research shows that attempting to restore normal expression of p53 protein by blocking another protein that normally degrades p53 can have the perverse effect of protecting mutated p53 and promoting metastasis.

The p53 gene is inactivated in a number of types of cancer. Its normal role is to halt the division of a defective cell and then force the cell to kill itself or deprive the cell of its ability to reproduce. As such, reactivation of p53 is thought to have great therapeutic potential.

Normally, p53 levels are low, but it springs into action in response to DNA damage or activation of cancer-promoting genes, or oncogenes......... Posted by: Andria      Read more         Source

May 22, 2008, 10:14 PM CT

OHSU Discovery May Lead to Early Cancer Detection

OHSU pancreas cancer expert Brett Sheppard, M.D., and his colleagues in the OHSU Oregon Stem Cell Center, have developed antibodies that recognize pancreas cancer; Sheppard is presenting these findings this week during Digestive Disease Week in San Diego.

This week scientists in the Oregon Health & Science University (OHSU) Oregon Stem Cell Center and the OHSU Digestive Health Center are shining a new ray of hope on patients with pancreas cancer. They've developed new reagents, or antibodies, that can recognize this often lethal disease. This important discovery may one day lead to earlier detection and therapy.

The new antibodies recognize a small number of normal pancreas cells, specifically cells involved in the transport of enzymes out of the pancreas, but recognize a number of more cells in pancreas cancer tissue. In addition to recognizing pancreas cancer, these antibodies recognize gastrointestinal cancers.

"The next step is to use these antibodies in a sensitive screening test to determine their full potential in diagnosis of this devastating disease," said Brett Sheppard, M.D., study co-investigator and pancreas cancer surgeon in the OHSU Digestive Health Center.

Sheppard, who also is professor and vice chairman of surgery in the OHSU School of Medicine and member of the OHSU Cancer Institute, will present these findings this week at Digestive Disease Week 2008 (Abstract No. 1838: "Development of Monoclonal Antibodies to Aid in the Diagnosis of Pancreatic Cancer")......... Posted by: Andria      Read more         Source

May 18, 2008, 9:42 PM CT

M. D. Anderson nurse addresses lymphedema

A poster session presented today by The University of Texas M. D. Anderson Cancer Center at the Oncology Nurses Society 33rd Annual Congress, observed that early nursing intervention and implementation of effective strategies can lead to a decrease in the occurence rate of lymphedema, better management of chronic lymphedema and improved quality of life in patients with breast cancer.

The literature review, led by Mattie J. Sennett McDowell, RN, BSN, a research nurse in the Department of Breast Medical Oncology at M. D. Anderson, examined 20 years of data about the prevention, management and care of upper extremity lymphedema (ULE), or lymphedema that occurs in the arms, in patients with breast cancer. The goal of the review was to identify a comprehensive list of existing evidenced-based strategies that nurses and hospitals can use in caring for their patients.

"Women are living longer as breast cancer therapys get better, but at the same time, they face more devastating side effects like lymphedema," McDowell said. "So a number of women present with the symptoms, yet it is understudied and not well understood. More can to be done to proactively recognize and address lymphedema in patients with breast cancer."

ULE is an often a distressing and debilitating side effect of breast cancer therapy in which protein-rich fluid in the tissue of the arms accumulates and obstructs the lymph vessels. As per the National Lymphedema Network, approximately 15 to 20 percent of all patients with breast cancer are affected by ULE. Its development can be triggered by breast cancer diagnostic procedures, radiation, surgery or environmental factors. It also can can occur immediately after therapy or a number of years down the road. ULE, which can make simple tasks such as picking up children, getting dressed or exercising painful, has a detrimental impact on the patient's quality of life......... Posted by: Andria      Read more         Source

May 13, 2008, 7:56 PM CT

Chemical Compound Prevents Cancer In Lab

While researching new ways to stop the progression of cancer, scientists at the University of Oklahoma Health Sciences Center, have discovered a compound that has shown to prevent cancer in the laboratory.

The compound, which still faces several rounds of clinical trials, successfully stopped normal cells from turning into cancer cells and inhibited the ability of tumors to grow and form blood vessels. If proved to be successful tests continue, scientists eventually hope to create a daily pill that would be taken as a cancer preventive.

"This compound was effective against the 12 types of cancers that it was tested on," said Doris Benbrook, Ph.D., principle investigator and researcher at the OU Cancer Institute. "Even more promising for health care is that it prevents the transformation of normal cells into cancer cells and is therefore now being developed by the National Cancer Institute as a cancer prevention drug".

The synthetic compound, SHetA2, a Flex-Het drug, directly targets abnormalities in cancer cell components without damaging normal cells. The disruption causes cancer cells to die and keeps tumors from forming.

Flex-Hets or flexible heteroarotinoids are synthetic compounds that can change certain parts of a cell and affect its growth. Among the diseases and conditions being studied for therapy with Flex-Hets are polycystic kidney disease, kidney cancer and ovary cancer......... Posted by: Andria      Read more         Source

April 30, 2008, 6:06 PM CT

'Destruct' triggers may be jammed in tumor cells

Tumor cells living in the cross hairs of radiation or chemotherapy may be able to escape death because their self-destruct mechanisms are jammed, say University of Florida researchers writing in a recent issue of Developmental Cell.

Researchers studying fruit fly cells discovered that slight changes in the protein scaffolds that support the genes reaper and hid aptly named for their roles in triggering cell death cause the cells to become naturally resistant to X-rays during early development.

It turns out that a piece of DNA that is mandatory for mediating this process of cell death is blocked, said Lei Zhou, Ph.D., an associate professor of molecular genetics and microbiology in the UF College of Medicine. When it is blocked, the cells just dont die, even when subjected to heavy doses of radiation. This may be what is happening in some resistant cancer cells. The pro-apoptotic genes cannot be induced to cause cell death.

The study may be the first to link apoptosis, the gene-driven process that leads to the necessary destruction of old, damaged, or infected cells, with epigenetics the study of how gene function changes even when the genes themselves dont change.

Researchers think that defects in cell death regulation may be responsible for tumor formation and the spread of cancer, because the cells escape the safeguards that normally clean up cancerous cells......... Posted by: Andria      Read more         Source

April 22, 2008, 9:05 PM CT

Cells on the Road to Cancer

Using a common virus as a tool for investigating abnormal cell proliferation, a team led by researchers at Cold Spring Harbor Laboratory (CSHL) has succeeded in clarifying an intricate series of biochemical steps that shed light on a way that cancer can begin.

The team's findings are the latest in a long and distinguished line of research at CSHL involving adenovirus, a type of virus that causes the common cold in people, but whose genome contains known oncogenes -- genes whose expression can promote cancer under certain conditions.

"Adenovirus carries many cooperating genes that modulate cell growth in ways we're interested in," said William Tansey, Ph.D., who, along with CSHL professors Scott Lowe, Ph.D., and Gregory Hannon, Ph.D., is one of the team's co-leaders and corresponding author of a paper would be published April 22 in Proceedings of the National Academy of Sciences. Other team members include molecular biologists from Stony Brook University in New York.

Using a Tumor Virus to Illuminate Function

The team focused on an adenoviral oncogene called E1A, and a protein that it codes for with the same name. "Both have received a great deal of attention over the years," said Dr. Tansey, "and to understand why, it helps to understand why viruses -- in this case, adenovirus, a DNA tumor virus -- is useful to us. We use them as you would use a flashlight, to illuminate important processes inside the cell that help us understand what goes awry in oncogenesis"......... Posted by: Andria      Read more         Source

April 21, 2008, 9:11 PM CT

Obesity, inactivity as common among cancer survivors

EdmontonNew research supported by the Canadian Cancer Society shows that a number of cancer survivors in Canada are overweight and inactive, which could put them at risk for health problems, including their cancer returning.

These findings tell us that we need to look at ways to better support cancer survivors to become more active and to maintain a healthy body weight, says Dr. Kerry Courneya, professor and Canada Research Chair at the University of Alberta in Edmonton, and affiliated scientist with the Centre for Behavioural Research and Program Evaluation. We know that physical inactivity and obesity are risk factors for developing cancer. These are also risk factors for the recurrence of cancer. Lifestyle is just as important after diagnosis.

"A cancer diagnosis can have a profound effect on people and their families, says Heather Chappell, senior manager of Cancer Control Policy at the Canadian Cancer Society. These important findings will help in developing ways to provide effective support for cancer patients. Even small changes can make a difference for patients, such as including a moderate amount of exercise and healthy eating in their therapy and recovery period, if and when they can.

Dr. Courneya and his research team analyzed data from a 2005 Community Health Survey of more than 114,000 adults. The studythe first of its kind in Canadapublished recently in the journal Cancer, showed that:........ Posted by: Andria      Read more         Source

April 21, 2008, 8:15 PM CT

Cancer cells spread by releasing 'bubbles'

A new fundamental mechanism of how tumour cells communicate has just been discovered by the team of Dr. Janusz Rak at the Research Institute of the McGill University Health Centre (MUHC) in collaboration with Dr Guha from the University of Toronto.

The cancer cells are able to communicate with their more healthy counter-parts by releasing vesicles. These bubble-like structures contain cancer-causing (oncogenic) proteins that can trigger specific mechanisms when they merge into non or less-cancerous cells. These findings could change our view on how malignant tissues work and lead to major clinical innovations. They were published on April 20 in the on-line edition of Nature Cell Biology.

The surface of some brain tumour cells has long been known to express a mutated version of what is called the variant III epidermal growth factor receptor (EGFRvIII). Eventhough this factor is expressed only in a fraction of tumour cells, it has a major impact on the malignancy of the whole tumor. How could this cellular minority have such an important impact" This mechanism was still unknown until now.

This study shows that the mutated EGFRvIII triggers production of small vesicles that project from the cell membrane and that carry mutated copies of EGFRvIII on their surfaces. They were baptised oncosomes. Surprisingly enough, this shows that oncoproteins are not always confined to the cell that produced them. In this case they even migrate!........ Posted by: Andria      Read more         Source

April 17, 2008, 8:25 PM CT

Tiny magnets offer breakthrough in gene therapy for cancer

A revolutionary cancer therapy using microscopic magnets to enable 'armed' human cells to target tumours has been developed by scientists funded by the Biotechnology and Biological Sciences Research Council (BBSRC). Research published online today (17 April) in the journal, Gene Therapy, shows that inserting these nanomagnets into cells carrying genes to fight tumours, results in a number of more cells successfully reaching and invading cancerous tumours.

Using human cells as delivery vehicles for anti-cancer gene treatment has long been an attractive approach for treating tumours, but these cells commonly reach tumours in insufficient numbers to effectively attack them. Now, a new 'magnetic targeting' method has been developed to overcome this problem by Professor Claire Lewis at the University of Sheffield, Professor Jon Dobson at the University of Keele, and Professor Helen Byrne and Dr. Giles Richardson at the University of Nottingham.

The technique involves inserting nanomagents into monocytes - a type of white blood cell used to carry gene treatment - and injecting the cells into the bloodstream. The scientists then placed a small magnet over the tumour to create a magnetic field and observed that this attracted a number of more monocytes into the tumour......... Posted by: Andria      Read more         Source

April 13, 2008, 8:58 PM CT

Vitamin D and calcium influence cell death in the colon

Scientists at Emory University are learning how vitamins and minerals in the diet can stimulate or prevent the appearance of colon cancer.

Emory researchers will present their findings on biological markers that could influence colon cancer risk in three abstracts at the American Association for Cancer Research meeting in San Diego.

In a clinical study of 92 patients, supplementing diet with calcium and vitamin D appeared to increase the levels of a protein called Bax that controls programmed cell death in the colon. More Bax might be pushing pre-malignant cells into programmed cell death, says Emory researcher Veronika Fedirko, who will present her team's results (abstract 464).

Prior studies have shown that calcium and vitamin D tend to reduce colon cancer risk.

"We were pleased that the effects of calcium and vitamin D were visible enough in this small study to be significant and reportable," Fedirko says. "We will have to fully evaluate each marker's strength as we accumulate more data".

The studies of colorectal biopsy samples are part of a larger effort to identify a portfolio of measurements that together can gauge someone's risk of getting colon cancer, says Roberd Bostick, MD, MPH, professor of epidemiology at Emory's Rollins School of Public Health......... Posted by: Andria      Read more         Source

April 9, 2008, 9:49 PM CT

A better mouse model for cancer research

Scientists at Boston College have developed the first laboratory mouse model that mimics cancers spread through the human body. Using their novel cell line, the team discovered one of the bodys primary defensive cells plays a role in cancers attack.

The development of a new animal model a line of cancer cells injected into a laboratory mouse that displays the full spectrum of systemic metastatic cancer in humans removes a "scientific stumbling block" in advancing cancer research and potential therapys, as per Boston College Biologist Thomas Seyfried, whose findings appear this week in the online version of the International Journal of Cancer and will be presented at the annual meeting of the American Association of Cancer Research in San Diego.

"What we have developed is the first model in the mouse that replicates all of the hallmarks of metastatic cancer," said Seyfried, the project leader. Now, we have a tool that can be effective in identifying basic mechanisms and new therapies to treat the disease.

Scientists produced two cell lines that when injected into mice express all the major biological processes of metastasis. A third line, when injected, grew rapidly, but did not lead to metastatic cancer.

Prior mouse models contain limitations in effectiveness and speed. A number of models fail to produce cancer in each animal subject and it often takes several months before cancer is detected. In other models, cancer cells are transplanted into animals with disabled immune systems. Within three weeks, the two Seyfried models produced tumors in 100 percent of the mice, which had healthy immune systems......... Posted by: Andria      Read more         Source

April 8, 2008, 10:24 PM CT

Double binding sites on tumor target

Scientists from the University of Pennsylvania School of Medicine and his colleagues at Merck Serono Research in Gera number of have observed that two drugs bind to receptor sites on some tumors in different places at the same time, suggesting the possibility of a new combination treatment for certain types of cancer.

An increasing number of therapies targeting tumors that have proteins called epidermal growth factor receptors (EGFR) sitting on their surface are already being used in the clinic or are in late stages of development. For example, Herceptin is an established therapy for certain types of breast cancer and Erbitux and Vectibix are in use for other types of cancer. An additional drug called matuzumab is in phase II clinical trials.

Three years ago, Kate Ferguson, PhD, Assistant Professor of Physiology, and his colleagues determined the precise molecular details of how Erbitux, a colorectal and head and neck cancer drug, binds to its target on cancer cells. EGFR drugs halt cell proliferation by blocking EGFRs molecular doorway, keeping hormones from binding and signaling tumor growth. X-ray crystallography provided a snapshot of the interaction between Erbitux and the extracellular component of the cancer cells receptors.

As is characteristic of a number of epithelial cancers - such as cancers of the colon, head and neck, breast, ovary, lung, and pancreas - the surface of cancer cells possess abnormally high levels of EGFR. In a cancer cell, an extracellular hormone binds to the outer piece of EGFR, and causes the inside part to kick off a series of reactions that signal the malignant cell to replicate and divide......... Posted by: Andria      Read more         Source

March 26, 2008, 9:53 PM CT

Anti-cancer drugs and new de-methylating agents

Scientists at the National Sun Yat-Sen University and Kaohsiung Medical University, Kaohsiung, Taiwan have revealed a new mechanism by which nonsteroidal anti-inflammatory drugs (NSAIDs) attenuate tumor invasion and metastasis. The research, would be reported in the April 2008 issue of Experimental Biology and Medicine, provides new insights for the understanding of the anti-cancer effects of NSAIDs.

NSAIDs have been used for the suppression of pain and inflammation in the clinic for a number of years. The main targets of these drugs are cyclooxygenases (COXs) which play critical roles in maintaining physiological homeostasis, mediating inflammatory reactions and promoting tumorigenesis. However, COX-independent effects are also important for the inhibition of cancer development by NSAIDs. Indeed, NSAIDs are considered as a novel class of effective chemopreventive drugs.

The research team, led by Wen-Chun Hung, Dean of College of Science, National Sun Yat-Sen University, and a recent doctorial graduate Mei-Ren Pan and two collaborators Hui-Chiu Chang and Lea-Yea Chuang of Kaohsiung Medical University observed that NSAIDs up-regulated several anti-metastatic genes including secreted protein acidic and rich in cysteine (SPARC), thrombospindin-1 (TSP-1), TSP-3 and tissue inhibitors of metalloproteinase-2 (TIMP-2) in human lung cancer cells. Our functional assay suggested that increases of SPARC and other anti-metastatic genes were important for NSAIDs to inhibit tumor invasion and metastasis said Wen-Chun Hung. More importantly, we elucidated the underlying mechanism and demonstrated that up-regulation of SPARC in human lung cancer cells was mediated via inhibition of DNA methyltransferases (DNMTs) expression and promoter de-methylation. This is the first report to show that NSAIDs may inhibit the expression of DNMTs to reverse promoter methylation and to reactivate gene transcription......... Posted by: Andria      Read more         Source

March 16, 2008, 9:29 PM CT

Halting the growth of a childhood brain cancer

A discovery by St. Jude Childrens Research Hospital researchers suggests a safer way to treat medulloblastoma, a rare but often fatal childhood brain tumor. The group observed that one of the brains signaling pathways inhibits the growth of the highly aggressive cancer cells.

The scientists discovered that three proteins, designated BMP2, BMP4 and BMP7, halted the growth of medulloblastoma tumors and induced the cancerous cells to develop into normal neurons.

We think we have identified a pathway that can be used to prevent tumor formation and a potential target for treatment, said Martine F. Roussel, Ph.D., a member of the St. Jude Department of Genetics and Tumor Cell Biology. A report on this work appears in the March 15 issue of Genes & Development. Roussel is the papers senior author.

Medulloblastoma occurs in the cerebellum, which is located in the lower, rear part of the brain. This cancer strikes about 350 young children in the United States annually. Eventhough treated patients have an overall five-year survival rate of 70 percent, conventional therapies combining surgery, irradiation and chemotherapy frequently lead to permanent neurocognitive impairment.

Several research teams are seeking to decipher the intricate signaling mechanisms that govern the proliferation of cells called granule neuron progenitors (GNPs). These cells go on to develop into neurons in the cerebellum during the first year of life. But the disruption of this differentiation process can trigger medulloblastoma......... Posted by: Andria      Read more         Source

March 12, 2008, 9:43 PM CT

Cause of severe allergic reaction to cancer drug

Clinicians have been perplexed by the fact that some patients given the drug cetuximaban immune-based treatment usually used to treat persons diagnosed with head and neck cancer, or colon cancerhave a severe and rapid adverse reaction to the drug. Sometimes the reaction includes anaphylaxis, a life-threatening condition characterized by a drop in blood pressure, fainting, difficulty breathing, and wheezing. Now scientists funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, have discovered that specific pre-existing antibodies cause the severe reaction to the drug. This discovery in turn has enabled them to explain the unusual geographic pattern of this reaction seen among individuals in the United States. The unusual findings of this investigation appear in a report reported in the March 13 edition of the New England Journal (NEJM).

These intriguing research findings not only are potentially important to physicians treating certain cancer patients, but also may have broader implications for the use of immunotherapies for other diseases, notes Anthony S. Fauci, M.D., NIAID director.

NIAID grantee Thomas Platts-Mills, M.D., Ph.D., who heads the Division of Allergy and Clinical Immunology at the University of Virginia, led a research study to investigate the cause of the clinical problem with cetuximab. Their newly reported findings are of immediate importance in the care of cancer patients, says Dr. Platts-Mills. Because of the widespread use of cetuximab in cancer therapy, it may be useful to pre-screen patients for specific IgE antibodies to cetuximab to identify those who are at risk for serious adverse reactions, including anaphylaxis......... Posted by: Andria      Read more         Source

March 9, 2008, 6:06 PM CT

Fugitive cancer cells can be blocked

Cancer cells get a helping hand from platelets, specialized blood cells involved in clotting. Platelets shelter and feed tumor cells that stray into the bloodstream, making it easier for cancer to spread, or metastasize. Research at Washington University School of Medicine in St. Louis suggests that inactivating platelets could slow down or prevent metastasis.

In advance online publication in the Journal of Cellular Biochemistry, the scientists report that a combination of two platelet inhibitors reduced the number and size of breast cancer or melanoma tumors that grew in the bones of laboratory mice.

One of the drugs was aspirin, a widely used inhibitor of platelet clotting. The other was an experimental drug, APT102, which also prevents platelet clotting, but by a different mechanism. Both drugs were needed to reduce bone tumors.

"Past research has shown that tumor cells activate platelets and that mice with defective platelets have significantly fewer metastases," says Katherine Weilbaecher, M.D., assistant professor of medicine and of cell biology and physiology. "We also know that platelets have several traits that can aid tumor cells, and we are working to break up that potentially lethal partnership".

Metastasis of cancer cells to sites away from the main tumor can cause pain and other symptoms and greatly increases the likelihood a patient will die of the disease. In fact, more than 90 percent of cancer deaths are the result of metastasis, which is difficult to control with current therapies......... Posted by: Andria      Read more         Source

March 5, 2008, 8:56 PM CT

Updated colorectal cancer screening guidelines

The American Cancer Society, the American College of Radiology, and the U.S. Multi-Society Task Force on Colorectal Cancer (a group that comprises representatives from the American College of Gastroenterology, American Gastroenterological Association, and American Society for Gastrointestinal Endoscopy) have released the first-ever joint consensus guidelines for colorectal cancer screening. The guidelines add two new tests to the list of recommended options: stool DNA (sDNA) and CT colonography (CTC), also known as virtual colonoscopy, and for the first time include a preference for screening tests that can not only detect cancer early but also detect premalignant polyps, as those tests provide a greater potential for cancer prevention through polyp removal.

The guidelines, which represent the most current scientific evidence and expert opinion available, also outline quality elements essential to each of the recommended testing methods. They will appear in the May/recent issue of CA: A Cancer Journal for Clinicians, and are published early online on CA First Look and will also be published in upcoming issues of the journals Gastroenterology and Radiology.

In addition to the new tests, the focus on quality and the new delineation of tests into two major types, the expert panel also concluded that any proposed colorectal screening test that has not been shown in the medical literature to detect the majority of cancers present at the time of testing should not be offered to patients for colorectal cancer screening. That includes some types of previously endorsed guiaic-based stool tests......... Posted by: Andria      Read more         Source

March 4, 2008, 5:38 PM CT

PET/CT planning beneficial for head and neck cancer patients

Using a combination of positron emission tomography (PET) and computed tomography for radiation treatment therapy planning in head and neck carcinoma patients provides for excellent, local and regional disease control when in comparison to CT alone, as per a research studyin the March 1 issue of the International Journal for Radiation Oncology*Biology*Physics, the official journal of the American Society for Therapeutic Radiology and Oncology.

CT has been the traditional choice for staging and radiation treatment therapy planning for head and neck squamous cell carcinomas, which account for approximately 5 percent of malignancies worldwide; but PET has been shown to have advantages over CT and other imaging modalities in detecting primary tumors, involved lymph nodes and distant metastatic disease not clearly otherwise identified. PET alone does have several disadvantages though, such as poor related to precise anatomic structures, but these negative impacts are significantly reduced when PET and CT are combined by fusing the separate scans taken on a hybrid scanner.

While it has been proven in several studies that PET/CT imaging is feasible for head and neck radiation treatment planning, very few studies have been done to determine the clinical outcomes. So, scientists in the departments of Radiation Oncology, Radiology, Neoplastic and Related Disorders, and Otolaryngology at the Medical College of Wisconsin in Milwaukee conducted this study to evaluate the clinical outcomes, including overall survival, disease-free survival and the occurence rate of recurrence of patients receiving PET/CT-guided radiation treatment and the correlation of the clinical outcomes to the maximum standard uptake value obtained on the PET scan......... Posted by: Andria      Read more         Source

March 2, 2008, 8:41 PM CT

Arsenic aids tumor imaging

Arsenic associated with a drug that binds to the blood vessels of malignant tumors provides a powerful imaging agent that could one day allow physicians to detect hard-to-find tumors and more closely monitor cancers response to treatment, scientists at UT Southwestern Medical Center have found.

The findings, based on animal studies and appearing in todays issue of Clinical Cancer Research, mark the first time arsenic has been used to label antibodies for the detection of tumors.

Dr. Philip Thorpe, professor of pharmacology at UT Southwestern and senior author of the study, helped create the cancer drug called bavituximab, an antibody that homes in on a specific molecular target on the blood vessels that feed tumors. Bavituximab is being tested in clinical trials to treat solid-tumor cancers in combination with chemotherapy.

While arsenic has been used as a poison for centuries, the dose of arsenic needed for imaging tumors is about one-millionth of that needed to cause toxicity, Dr. Thorpe said.

Arsenic-labeled bavituximab appears to be safe.

In the study, Dr. Thorpe and colleagues injected radioarsenic-labeled bavituximab into rats with prostate tumors. When the bavituximab bound to its target on the the tumor blood vessels, the tag-along arsenic created a hot spot that scientists then imaged using positron emission tomography methods. The radioactivity levels produced by the arsenic are comparable to those used in standard, routine imaging procedures in humans. The technique allowed them to locate and capture uncommonly clear images of the tumors. They also discovered that there was little or no detectable uptake of bavituximab by normal organs, including the liver, a common site where drugs become entrapped......... Posted by: Andria      Read more         Source

February 25, 2008, 9:26 PM CT

Chemo holidays for men with advanced prostate cancer

The double-blind, randomized study, led by principal investigator Tomasz Beer, M.D., recently was reported in the journal Cancer. Beer is the Grover C. Bagby Endowed Chair for Cancer Research, director of the OHSU Cancer Institute Prostate Cancer Program, and associate professor of medicine (hematology/medical oncology), OHSU School of Medicine.

Beer and his team wanted to know if men with metastatic, androgen-independent prostate cancer cancer that has spread from the prostate and is not affected by the male hormone, androgen could take a break from docetaxel, an intravenous chemotherapy delivery drug that is the gold standard therapy for androgen-independent prostate cancer. Docetaxel works by killing cancer cells and slowing cell growth. However, the drug also can cause side effects, such as hair loss, nausea, loss of appetite and increased chance for infections. Chemo holidays can be a much-needed vacation from these side effects.

Previous to this study, it wasnt known whether stopping chemotherapy would lead to therapy resistance.

We wanted to see if we could improve the quality of life for these patients by giving them time away from chemotherapy and possibly extend the time their cancer is controlled. Essentially, what we proved is that in selected subjects, chemotherapy holidays are feasible and provided meaningful breaks from therapy, said Beer......... Posted by: Andria      Read more         Source

February 14, 2008, 10:22 PM CT

Single reader with CAD more efficient

Single reading of screening mammograms with computer-aided detection (CAD) is more efficient than double reading and yields a higher sensitivity than the first reader in a double reading program, according to a study conducted by researchers at Charlotte Radiology in Charlotte, NC. In addition, the readings with CAD had a significantly lower recall rate than double reading.

The double reading method consisted of the mammogram being first read by sub-specialized mammographers, with the second reading performed by either a specialist or a general radiologist who is certified in mammography. Single reading with CAD was performed by sub-specialized mammographers.

The study compared the recall rate, sensitivity, positive predictive value (PPV), and cancer detection rate of single reading with CAD to double reading and to the first reader in the double reading program in 231,221 mammograms from 2001-2005. The study shows that single reading with CAD was as effective at finding cancers as double reading and had a lower recall rate.

Because double reading is time consuming and not generally reimbursed, CAD has become increasingly popular in the United States as an alternative way to increase sensitivity, said Matthew Gromet, JD, MD, author of the study.

According to the study, statistically significant results included a lower recall rate with CAD compared to double reading (10.6% vs. 11.9%), increased sensitivity with CAD compared to the first reader (90.4% vs. 81.4%), and increased recall rate with CAD compared with the first reader (10.6% vs. 10.2%). The sensitivity of single reading with CAD was slightly higher than double reading (90.4% vs. 88.0%), although this difference did not reach statistical significance......... Posted by: Andria      Read more         Source

February 6, 2008, 8:18 PM CT

Gene Play Role in Skin Cancer Development

Scientists at the Burnham Institute for Medical Research (Burnham Institute) have provided genetic evidence that Activating Transcription Factor 2 (ATF2) plays a suppressor role in skin cancer development. ATF2 is a protein that regulates gene transcription, which is the first step in the translation of genetic code, in response to extracellular stresses such as ultraviolet light and ionizing radiation. This function of ATF2 in stress and DNA damage response suggests that it may also play a role in the formation of tumors.

Prior studies led by Ze'ev Ronai, Ph.D. have suggested an important role of ATF2 in melanoma development and progression. In this new study, published in this week's issue of Proceedings of the National Academy of Sciences of the United States of America, the Ronai laboratory, in collaboration with Nic Jones, Ph.D. from the University of Manchester UK, used a mouse model that expresses a transcriptionally inactive form of ATF2 in skin cells (keratinocytes). When the mice were subjected to chemically mediated skin carcinogenesis, tumors appeared faster and more frequently. These findings reveal that loss of ATF2 transcriptional activity in skin exposed to carcinogens enhances skin tumor formation, suggesting a tumor suppressor role for ATF2 in keratinocytes......... Posted by: Andria      Read more         Source

January 14, 2008, 5:21 PM CT

Fruit flies all aglow light the way to cancer prevention

A green glow from a fruit fly is giving scientists the green light when they are on the right path in their quest to develop compounds that help prevent cancer.

The glow, the result of some tinkering in Drosophila, the workhorse of the genetics world, lets scientists know when powerful cancer-prevention signals similar to those spurred by protective chemicals in broccoli, cabbage, and other foods, have been turned on in the organism.

The chemical signaling system is one of the major ways that the body defends itself against toxic assaults and threats like cigarette smoke, diesel exhaust, and dangerous microbes. A gene known as KEAP1 senses danger and then unleashes NRF2, which triggers rampant anti-oxidant activity in a cell.

Now researchers from the University of Rochester Medical Center have discovered that the pathway, long recognized in people and other animals, is active in fruit flies, too, opening the door to faster, less expensive ways to find compounds that spur our natural anti-oxidant activity. The work, funded by the National Cancer Institute, is published in the Jan. 15 issue of Developmental Cell.

This is one of the main mechanisms the body uses to fight off the things that give you cancer, said Dirk Bohmann, Ph.D., professor in the Department of Biomedical Genetics and a geneticist who studies fruit flies in an effort ultimately aimed at improving human health......... Posted by: Andria      Read more         Source

December 28, 2007, 8:04 AM CT

Cancer Is Too Complex For Easy Answers

Scientists who study cancer may be prone to drawing simplistic conclusions from the powerful molecular tools now available because they don't appreciate how complex the data is that is being generated, said a team of Georgetown University Medical Center (GUMC) researchers in the recent issue of Nature Reviews Cancer.

In a review article summing up the state of the field, they said cancer scientists should endeavor to better understand the issues these genomic and proteomic technologies create or conclusions from their research may be misleading.

"These tools have allowed us to see that nature is more complex than we thought, and while we don't yet know what the overarching biological rules are - such as the interrelationship between multiple signaling pathways that can lead to cancer development - we are trying to play the game like we do," said the review's lead author, Robert Clarke, Ph.D., D.Sc., professor of oncology and physiology & biophysics at the Lombardi Comprehensive Cancer Center at GUMC, where he co-directs the Breast Cancer Program. Clarke is the interim director of GUMC's Biomedical Graduate Research Organization, which is home to more than 60 percent of the University's biomedical research funding.

"The answers to our questions are probably there in the data," he said, "but the issue is whether we can get them using these complex tools and, also, how we will know they are right when we see them"......... Posted by: Andria      Read more         Source

December 20, 2007, 9:38 PM CT

Enzyme Target for Cancer Drugs

The veil has finally been lifted on an enzyme that is critical to the process of DNA transcription and replication, and is a prime target of antibacterial and anticancer drugs. Scientists with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) at Berkeley have produced the first three-dimensional structural images of a DNA-bound Type II topoisomerase (topo II) that is responsible for untangling coiled strands of the chromosome during cell division.

Preventing topo II from disentangling a cell's DNA is fatal to the cell, which is why drugs that target topo II serve as agents against bacterial infections and some forms of cancer. This first ever structural image of topo II should help in the development of future antibacterial and anticancer drugs that are even more effective and carry fewer potential side effects.

"Topo II has been called nature's magician because it literally can move one DNA segment through another," said James Berger, a biochemist and structural biologist who led this research. "The enzyme cleaves a double-stranded DNA, passes a second duplex through the break, and then immediately repairs the broken strands. This enables topo II to control the topology of DNA for chromosome segregation and disentanglement"......... Posted by: Andria      Read more         Source

December 13, 2007, 10:01 PM CT

Drug study for brain cancer shows promise

A clinical study conducted at Henry Ford Hospital on the use of a drug to extend the survival of patients with the most common and aggressive type of brain cancer, has yielded results that were significantly better than expected.

The randomized Phase II study focused on patients with glioblastoma multiforme (GBM), whose cancer had recurred after first- or second-line treatment. The study revealed that more than a third who were treated with Avastin (bevacizumab) alone, as well as more than half of those treated with Avastin in combination with the chemotherapy drug irinotecan, lived without further progression of the disease for a period of six months. In addition, no new or unexpected adverse effects from the use of Avastin were observed during the study.

This is very encouraging news, says Tom Mikkelsen, M.D., a neuro-oncologist who is the studys principal investigator at Henry Ford and co-director of the Hermelin Brain Tumor Center. "Historical estimates suggest that only 15 percent of patients with this aggressive type of brain cancer live without their cancer progressing within six months. Eventhough gliomas [fast-growing cancerous brain tumors] are nearly always incurable, use of a drug like Avastin may help to buy precious time for patients, as well as to preserve their physical and mental functions longer than was previously possible......... Posted by: Andria      Read more         Source

December 11, 2007, 10:23 PM CT

Cancer cell line resistant to new cancer therapy

They found the HDAC inhibitor-resistant cell line resistant to a number of therapies, including more standard therapy such as chemotherapy, but highly sensitive to heat shock protein 90, or hsp90, inhibitors, another emerging cancer therapy.

"As part of their resistance mechanisms, they acquired greater sensitivity to hsp90 inhibitors," says Dr. Bhalla, Cecil F. Whitaker Jr., M.D./Georgia Research Alliance Eminent Scholar in Cancer. "This creates a potential combination that can be tested in mouse models and ultimately clinical trials".

HDAC and hsp90 inhibitors are both being studied in combination with other cancer therapies but not each other. However the MCG researchers, who already have published work indicating a synergistic effect, were not surprised by what they found.

"Resistance to HDAC inhibitors is going to emerge, so you need a cellular model to understand mechanisms of resistance and an in vivo model, a mouse model typically, to test new combinations you design based on studies in culture," says Dr. Bhalla.

The scientists have put the cell line into a mouse model and other researchers already are asking for the resistant cell line, he says.

"This particular cell line can be used to really look at newer agents and new combinations in vitro and in vivo and see if they are safe and effective together," Dr. Fiskus says......... Posted by: Andria      Read more         Source